North and South America, At Night

Composite image of the Americas at night from the Suomi NPP satellite. Image Credit: NASA

Along with all of their space-exploration, planet-hunting, and astronomy-based endeavours, NASA also keeps a very keen eye on Earth. In fact, they have 18 satellites whose job it is to look only at Earth. And those 18 advanced satellites are helping us understand Earth in unprecedented scientific detail.

And they take pretty pictures, too.

NASA just released a night-time composite satellite image of North and South America. The image features data from the Suomi NPP (Suomi National Polar-orbiting Partnership) satellite overlaid on Blue Marble imagery of Earth. The image is from NASA’s e-book Earth At Night.

<Click to open the e-book> NASA has just released their new e-book Earth At Night featuring satellite images of Earth. Image Credit: NASA

Satellite imagery of Earth serves two purposes, and NASA is well aware of that. They provide crucial scientific information about the health of our planet and our activities and presence on Earth. But they also provide inspiring images for we non-scientists. And NASA hopes more of us find it engaging.

“Science not only changes what we know, but also how we think about our place in the cosmos.”

NASA Associate Administrator Thomas Zurbuchen.

In the foreword to their Earth At Night e-book, NASA Associate Administrator Thomas H. Zurbuchen said, “Our home planet is full of complex and dynamic cycles and processes. These soaring observers show us new ways to discern the nuances of light created by natural and human-made sources, such as auroras, wildfires, cities, phytoplankton, and volcanoes.”

Mount Etna on the island of Sicily, Italy, is Europe’s most active volcano. It’s not a night-time image, but it’s a fascinating one, and shows the high quality of the satellite imagery available to us today. Image Credit: USGS/NASA

There are daytime images in the e-book, but the bulk of them are night-time images, and they show how we have shaped the Earth as we inhabit it. The night-time images rely largely on Suomi NPP’s Visible Infrared Imaging Radiometer Suite (VIIRS.) Its “day-night band” works across a range of wavelengths and uses filters that allow features like city lights, gas flares, auroras, wildfires and reflected moonlight to come to the forefront. That level of detail helps make these images so compelling.

Not all of the images are from satellites. Astronauts onboard the International Space Station are treated to a spectacular display of the aurora australis while in orbit over Southern New Zealand on September 17, 2011. Image Credit: NASA

Some of the satellite images show how our resource extraction activities are widespread across Earth. Things like oil well fires and flaring, and even fishing show up in the images. They can provide important information on the status of fisheries and catch rates of certain species.

This Suomi NPP image shows squid-fishing boats off the east coast of South America. The fishermen use lights to attract their catch. They concentrate near important ocean currents and near the edge of the continental shelf, and scientists use these image to understand fish stocks and catch rates. Image Credit: NASA/SUOMI NPP

Some of the images in Earth at Night show how quickly an area can change when resources are discovered. The Eagle Ford Shale Play in Texas became an important source of hydrocarbons, and in a short time the surface was transformed. The change is apparent in both day and night time images.

This Suomi NPP image shows the light from the Eagle Ford Shale in Texas. All of the lights in the outline come from the electric glow of drilling equipment, worker camps, and other gas and oil infrastructure combined with flickering gas flares. These are daytime images of the Cotulla outline in the Eagle Ford Shale formation night-time image. In only 15 years, the area was transformed by a grid-work of roads and drilling platforms. Image Credit: LandSat 5/LandSat 8.

NASA’s Earth at Night e-book is a fascinating look at how the Earth has changed over the years. It shows in detail how our presence changes the Earth, and how the Earth has a life of its own, irregardless of our activities.

“Darkness is where dreamers and learners of all ages peer into the universe and think of questions about themselves and their space in the cosmos. Light is where they work, where they gather, and take time together.”